The present application relates generally to the field of image forming apparatus, and in particular, to sensors to detect the width of a media sheet as it moves along a media path within the image forming apparatus.
Image forming apparatus move a media sheet through an extended media path. The media sheet undergoes numerous image forming operations along the path such as initial input into the media path from an input tray or exterior input, image transfer area, and adhering the image to the media sheet. Problems can occur during these operations, especially if the device cannot anticipate and make adjustments to accommodate for different widths of media sheets.
In image forming apparatus with a fusing area, narrow media sheets moving through the fusing area may cause uneven heating of the fusing members. The uneven heating occurs between a first section of the fusing members that are contacted by the media sheets, and a second section that is not contacted by the media sheets. The first section maintains a first temperature range, while the second section maintains a second, higher temperature range. This uneven heating of the fusing members may result in inadequate fusing of the toner to the media sheets. The unequal heating may also decrease the life and reliability of the fusing members.
Another area affected by the width of the media sheets is the image transfer area. This area should be configured to prevent transfer of the image at a point off of the media sheet. Further, media sheets of differing widths may be moved along the media path in a different manner. This is especially evident when the media sheets are aligned to a particular reference location along the media path. Mishandling of the media sheets may result in media jams that can cause frustration, time, and money. Thus, there is a need for an effective manner to detect the width of a media sheet.